Automatic fire protection systems are one of the most widely used applications for fire protection. These system applications utilize fire fighting/protection instruments such as, for example, sprinklers and/or spray nozzles that are activated once the ambient temperature in an environment, such as a room or a building, exceeds a predetermined or threshold value. Once activated, the sprinklers and/or nozzles distribute fire-extinguishing fluid, preferably water, in the room or building.
In order to properly respond to the ambient threshold value, automatic sprinklers and nozzles are provided with a thermally responsive trigger assembly. These trigger assemblies support in place a closure member at the discharge outlet of the instrument. Once the threshold temperature is reached in the room or enclosure, the trigger assembly actuates and displaces the closure member allowing fire fighting fluid such as water to discharge from the outlet of the instrument. One type of trigger assembly is a fusible link as provided in an automatic sprinkler. The fusible link includes a link member having two halves in which a solder element holds the halves in place to support the closure member at the sprinkler outlet. The solder member is thermally rated to melt at a threshold temperature thus, allowing the halves to separate and displace the closure member for sprinkler operation. Another type of trigger assembly includes a bulb type trigger assembly provided in an automatic spray nozzle or automatic sprinkler. The bulb type trigger assembly includes a fluid contained within a glass bulb that supports the closure assembly at the sprinkler outlet. The fluid expands upon exposure to heat and at a sufficiently high temperature. The fluid can expand so as to shatter the glass bulb. Once the bulb shatters, the closure member can be displaced to allow for fluid discharge from the sprinkler outlet.
The trigger assemblies for automatic sprinklers and spray nozzles are generally fragile and can be subject to damage during shipping, storage and/or installation. For example, the trigger assembly in a sprinkler mounted to a branch pipe of a sprinkler system can be damaged by building materials such as, for example, dry wall, pipe or other obstructions that are moved about during construction. In addition, the trigger assemblies can be damaged when mishandled or dropped by an installer. When the trigger assembly is damaged, the entire sprinkler or nozzle generally must either be discarded and/or replaced which can be a significant cost to the manufacturer, supplier, installer and/or building owner.
To protect the trigger assembly during shipping and/or installation a cover or protection device can be disposed about the sprinkler such that the trigger assembly is shielded from damage. One known protector is shown and described in U.S. Pat. No. 6,669,111, which is directed to a protector for a thermally responsive member of a sprinkler head. Shown is a protector that pivots or separates about a hinge to envelop the frame arms of the sprinkler. Another protector is shown in Design Patent No. D498,818 and is more specifically directed to a bulb cover.
In October 2003, Underwriter's Laboratories, Inc. (“UL”) published UL Standard 1626 (October 2003) entitled “Residential Sprinklers For Fire-Protection Service UL-1626” (hereinafter “UL 1626”) which included Section 35A directed to impact test for protective covers. Section 35A is incorporated in its entirety by reference. The test of Section 35A established acceptable performance criteria for protective covers or devices configured to protect frangible bulb type sprinklers. According to the test, a frangible bulb type sprinkler with a protective cover installed shall not be damaged or leak when tested in manner outlined by Section 35A.2. The test of Section 35A was made effective Mar. 26, 2004. Similar impact test standards are established for commercial sprinklers in UL Standard publication “Automatic Sprinklers For Fire-Protection Service—UL 199” (Nov. 4, 2005) (hereinafter “UL 199”). Section 21 of UL 199 specifically provides standards and criteria for conducting an impact test for a protective cover substantially similar to those of UL 1626, Section 35A. The test of UL 199 Section 21 was made effective Sep. 26, 2004 and is incorporated in its entirety by reference. Another, but substantially similar test is provided for spray nozzles, in UL Standard 2351 entitled, “Spray Nozzles For Fire-Protection Service—UL 2351” (Jun. 4, 2004) (hereinafter “UL 2351”), which is incorporated herein in its entirety by reference. Section 30 of UL 2351, effective Dec. 4, 2005, specifically provides standards and criteria for conducting an impact test for a protective cover installed over a glass bulb type automatic nozzle. Accordingly, any sprinkler cover protection device supplied after Mar. 26, 2004 needs to comply with the impact standards of preferably UL 1626, Section 35A; UL 199, Section 21 and/or UL 2351, Section 30.